Add automated test for long running prepared transactions

Add an automated test in Python or csuite for long running prepared transactions.

At the start of the project, this will result in cache stuck (it should be disabled until the test doesn't hang, or timeout in a reasonable time).

This test should be able to use as verification for the correctness of the project implementation. 

Some configuration options for this test to be considered:

– Cache size to be used.

– Duration of test run.